It should be remembered that such rings are normally manufactured from a strip, shaped into a ring that is generally circular. The ring itself is naturally capable of being deformed because of the gap between its two ends which creates an elastic restoring moment used to provide the clamping. For a long time, it has been known to produce this type of ring by causing the two ends of a spring strip to overlap. A central cut-away portion of the strip forming the ring extends over a few centimetres to one of its ends to form a passage for the other which is reduced in width in order to be coincident with this passage. The two ends of the strip are fitted with lugs obtained by simple rectangular bending of their end parts towards the outside of the ring in such a way that using pincers fitted with jaws, one can easily bring the two lugs towards one another, that is to say increase the diameter of the ring which when released causes the elastic restoring moment necessary for the clamping.
Numerous tools for assembling and dismantling elastic rings are available to users and most of these tools, manual or automatic operate on the basis of very simple lever systems such as, for example x-shaped pincers.
The major disadvantage of these tools for elastic rings resides in the fact that for assembling hoses onto an automobile engine, for example, it is practically impossible to ensure that one obtains precise positioning of the ring on a sleeve. Actually, the ring, having a diameter clearly greater than the diameter of the sleeve to be clamped can find itself in any position when the two lugs on the ring are released in order to clamp it ; at this precise moment, the ring takes up a position that is totally random and generally uncontrollable by the operator who often cannot see it. It is even a common occurrence on assembly, that this type of ring released suddenly and positioned crosswise leads to the hose that is assembled on the end of the pipe being distorted. In the more favourable situation where the operator notices the problem, the correct positioning of a badly positioned ring requires a repeat operation that is often difficult because of the lack of accessibility that is generally the case. In any case, it is essential to unclamp the ring as little as possible in order to replace it in the correct position, which is often impossible.
In order to remedy such difficulties notably of access, one often has to use extended pincer systems which remain difficult to work with. Also known is the German utility model DE-29603425 pincers for the mounting and the disassembly of elastic rings that comprise pressure pincers connected to a slide forming a jaw that is movable by means of a flexible cable. This device while it permits more easy remote operation for the mounting and disassembly of the rings is characterized in that the slide assembly comprises a stop device in an open position for the ring, on which the operator must act for the final positioning of the same ring or for its removal in the case of disassembly; this device has the serious disadvantage that the operator is obliged to manipulate the slide assembly and the releasing system with just one hand, the other hand, in principle having to manipulate or to hold the pressure pincers. It would therefore appear to be extremely difficult to use the same hand for positioning and for releasing the ring at the same time, particularly when access is difficult. and a movable jaw capable of being linearly displaced in relation to the fixed jaw by actuating means situated remotely and linked to said tool by means of a cable connected on the one hand to the movable jaw and sliding inside a sheath that is advantageously flexible, one end of which is in abutment with the fixed jaw in order to allow the cable to slide, such a system being characterised in that the actuating means consist of two arms which are articulated on one and the same axis in such a way that they are separated in an angular sense, to such an extent that the distance between their free ends is at least equal to the maximum displacement of the movable jaw, when two handles respectively integral with the two arms are brought towards each other, the free end of one arm being used as a stop at the other end of the sheath while at the same time the cable which passes through it and is connected to the free end of the other arm, is allowed to slide freely.
This manipulation system, each arm of which together with its handle stays within the plane of their respective movements on the same side of a median line of the plane passing between the two arms, the two handles and their centre of articulation, is particularly advantageous for application to the mounting and dismantling of elastic rings even when they are situated at points with very difficult access, which is generally the case in the engines of presentday vehicles.
It is actually sufficient to match the fixed jaw and the movable jaw of the remotely operated tool for it to be inserted onto the lugs of an elastic ring that is completely standard and not pre-stressed. For dismantling, it is very easy to engage the two jaws around the lugs of the ring to be unclamped using for example a left hand with the right hand holding the remote handling device, in the position with the handles apart, in order to facilitate the entry of the jaws onto the lugs. For dismantling, a simple pressure with the right hand is sufficient to bring the two handles towards each other, which determines a torque that is enough to bring the movable jaw closer to the fixed jaw which as a consequence increases the diameter of the ring and brings about the required unclamping. Conversely, if one wishes to reposition the ring which has been unclamped into the correct position or into another position on the hose, one has only to gently release the two handles of the remote handling device until the left hand can easily release the movable jaw and fix the lugs of the ring.